A fin flash is part of the national markings of the military aircraft of a number of countries. In addition to the insignia displayed on the wings and fuselage, usually in the form of roundels, an additional marking known as a fin flash may also be displayed on the fin or rudder. A fin flash often takes the form of vertical, horizontal or slanted stripes in the same colours as the main insignia and may be referred to as rudder stripes if they appear on the rudder instead of the fin, as with the Armee de l'Air of France. Alternatively, a national flag or a roundel may be used.